Influence of seafood and vitamin supplementation on maternal and umbilical cord blood mercury concentration

Background The purpose of this study was to examine the influence of maternal seafood consumption and vitamin supplementation during pregnancy on maternal and umbilical cord blood mercury (Hg) concentration. Methods In this study of 145 healthy pregnant women (mean age 28.1 ± 5.2 years), we administered questionnaires, collected paired maternal/umbilical cord blood samples, and measured the anthropometrics of newborns. Blood Hg concentration was assayed by inductively coupled plasma-mass spectrometry. Results Sixty-one of these women (42.1%) used vitamins >3 times/wk prenatally. Seventy-eight of our study participants (61.9%) reported eating higher amounts of seafood during pregnancy. We found a strong correlation (r = 0.76, p < 0.001) between Hg levels in the paired maternal/umbilical cord blood samples. Mothers with high seafood consumption had a 2.91-fold greater risk (adjusted odds ratio 2.91, 95% confidence interval: 1.04–8.15, p = 0.042) of high Hg levels (>5.8 μg/L). However, mothers whose prenatal vitamin intake was >3 times/wk were found to have low Hg levels (≤5.8 μg/L) (adjusted odds ratio 0.06, 95% confidence interval: 0.01–049, p = 0.008). Conclusion High seafood consumption was an independent risk factor for high maternal Hg level, while vitamin supplementation was a protective factor. Further study is needed to investigate the specific effect of vitamins on Hg level.